Jigsaw puzzles have been in existence for about two hundred fifty years. Usually, a piece of art is laminated or printed on a wooden, paper or plastic board and the board is subsequently cut into many, sometimes interlocking, pieces. It is then a challenging activity to reassemble the pieces by matching shapes, colon, and patterns. The usual form of such puzzles is a flat, two-dimensional scene. When the puzzle comprises hundreds of pieces, a horizontal surface must be chosen upon which to solve the puzzle which is at least as large in both directions as the puzzle. In practice, the puzzle requires about twice as much area unassembled as when it is assembled. There have been examples of thick, wooden puzzles which could stand on their edges as in animal puzzles for children and jigsaw puzzles of many different materials which have been made to stand on their edges by means of a base or stand into which the edge is inserted. These vertical puzzles have involved relatively few pieces. There have been jigsaw puzzles known as inlays which can be assembled into trays comprising a frame around non interlocking interior pieces and a bottom or backing board which supports the assembly activity and supports the interior pieces when assembled. There has never been a method of solving an ordinary jigsaw puzzle with hundreds of pieces of paper board laminated with printed paper in a vertical format.
Jigsaw puzzle workers enjoy a challenge. The greater the challenge, the greater their pleasure and satisfaction. The only skills required, however, have always been the matching of shapes, colors, and patterns. The puzzles have only been made more difficult by making the shapes of pieces more nearly identical, by making the colors more and more similar, and by making any differences in patterns of line and color less discernible, and of course by increasing the number of pieces.